Atrial echo beats as a novel mechanism of periodic fluctuation in cycle length of atrial tachycardia.

Atrial echo beats due to a dual-atrioventricular nodal pathway are a possible cause of fluctuating tachycardia in cycle length (CL) but have not been reported so far. Here, we present a case of an 82-year-old man with symptomatic atrial tachycardia (AT), which was accompanied by periodic fluctuations in atrial sequence at the coronary sinus. Electrophysiological study (EPS) for atrioventricular conduction and three-dimensional (3D) electro-anatomical mapping system explained that the mechanism of periodic fluctuations was due to atrial echo beats through a dual-atrioventricular nodal pathway.

Sudden Cardiac Arrest Due to Spontaneous Coronary Artery Rupture - A Case Report with a Diagnostic Challenge.

Spontaneous coronary artery rupture (SCAR) is a rare, life-threatening disease, and the diagnosis is often challenging. We herein report a 70-year-old man who suffered sudden cardiac arrest due to SCAR with pericardial fluid. At first, emergent coronary angiography (CAG) failed to detect abnormalities. The emergent operation revealed that the presence of pericardial fluid was caused by bleeding that had spontaneously occurred at the left circumflex artery (LCx). A careful retrospective CAG review showed slight contrast spillage from the distal LCx. SCAR should be suspected in patients with unknown etiology of pericardial effusion, and careful inspection of CAG is necessary.

A comprehensive validation of very early rule-out strategies for non-ST-segment elevation myocardial infarction in emergency departments: protocol for a multicentre prospective cohort study.

INTRODUCTION: Recent advances in troponin sensitivity enabled early and accurate judgement of ruling-out myocardial infarction, especially non-ST elevation myocardial infarction (NSTEMI) in emergency departments (EDs) with development of various prediction-rules and high-sensitive-troponin-based strategies (hs-troponin). Reliance on clinical impression, however, is still common, and it remains unknown which of these strategies is superior. Therefore, our objective in this prospective cohort study is to comprehensively validate the diagnostic accuracy of clinical impression-based strategies, prediction-rules and hs-troponin-based strategies for ruling-out NSTEMIs. METHODS AND ANALYSIS: In total, 1500 consecutive adult patients with symptoms suggestive of acute coronary syndrome will be prospectively recruited from five EDs in two tertiary-level, two secondary-level community hospitals and one university hospital in Japan. The study has begun in July 2018, and recruitment period will be about 1 year. A board-certified emergency physician will complete standardised case report forms, and independently perform a clinical impression-based risk estimation of NSTEMI. Index strategies to be compared will include the clinical impression-based strategy; prediction rules and hs-troponin-based strategies for the following types of troponin (Roche Elecsys hs-troponin T; Abbott ARCHITECT hs-troponin I; Siemens ADVIA Centaur hs-troponin I; Siemens ADVIA Centaur sensitive-troponin I). The reference standard will be the composite of type 1 MI and cardiac death within 30 days after admission to the ED. Outcome measures will be negative predictive value, sensitivity and effectiveness, defined as the proportion of patients categorised as low risk for NSTEMI. We will also evaluate inter-rater reliability of the clinical impression-based risk estimation. ETHICS AND DISSEMINATION: The study is approved by the Ethics Committees of the Kyoto University Graduate School and Faculty of Medicine and of the five hospitals where we will recruit patients. We will disseminate the study results through conference presentations and peer-reviewed journals.

Comparison of uninterrupted anticoagulation with dabigatran etexilate or warfarin in the periprocedural period for atrial fibrillation catheter ablation: Results of the Japanese subgroup of the RE-CIRCUIT trial.

Background: There are limited data on uninterrupted anticoagulation with direct oral anticoagulants during catheter ablation for atrial fibrillation (AF), particularly in Japan. We planned a subgroup analysis of the RE-CIRCUIT study, comparing the use of uninterrupted dabigatran therapy with warfarin therapy during catheter ablation among the Japanese subgroup and with that in the total population. Methods: The RE-CIRCUIT study utilized a prospective, randomized, open-label, blinded endpoint design, and the primary endpoint was the incidence of major bleeding events (MBEs). Patients were randomized to uninterrupted dabigatran 150 mg twice daily or warfarin. In this study, we analyzed the results in Japanese patients. Results: Of 704 enrolled patients in the study, 112 Japanese patients were randomized to dabigatran (n = 65) or warfarin (n = 47). MBEs were experienced by two patients: one in the dabigatran group (1.6%, cardiac tamponade) and one in the warfarin group (2.2%, groin hematoma) (risk difference vs warfarin -0.6%; 95% CI -5.8, 4.7). Within the Japanese subgroup, there were no thromboembolic events in both groups. Conclusion: While not designed to show statistical difference between two treatment groups, our results from the Japanese subgroup supported those from the overall population. Furthermore, this study provided clinical information regarding MBE, especially cardiac tamponade, in Japanese patients.

Early detection of twiddler syndrome due a congestion alert by remote monitoring.

There are often false-positive alerts of thoracic impedance monitoring; however, the "false-positive alerts" might indicate any clinical problem of patient. In the present case, an alert for a drop in intrathoracic impedance, which generally indicates exacerbation of heart failure, enabled early detection of twiddler syndrome.

Resolution of left ventricular thrombus secondary to tachycardia-induced heart failure with rivaroxaban.

A 42-year-old man was admitted to our hospital because of lumbago and tachycardia-induced heart failure. Transthoracic echocardiography revealed impaired left ventricular function and a ball mass of thrombus in the left ventricle (LV). He was found to have systemic embolism in the spleen, kidneys, brain, and limbs. The patient was treated with limb thrombectomy followed by anticoagulation. Seven days after the direct factor Xa inhibitor, rivaroxaban, was initiated, transthoracic echocardiography was repeated, revealing disappearance of the LV thrombus without any clinical signs of cardiogenic embolism. His heart failure responded well and the LV wall motion had improved. This case suggests rivaroxaban has fibrinolytic effects on thrombi even in the LV.

A case of idiopathic giant cell myocarditis with a past history of sarcoidosis.

A 70-year-old woman with back pain and breathlessness was referred to our hospital for suspected myocardial infarction. Coronary angiogram was normal and endomyocardial biopsy showed inflammatory cell infiltrates consisting of eosinophils and multinucleated giant cells. The clinical course was hemodynamically fulminant, but steroid therapy improved the cardiac function. Interestingly, this patient had a past history of sarcoidosis. We diagnosed this case with idiopathic giant cell myocarditis (IGCM) from its clinical course. However, whether IGCM and cardiac sarcoidosis belong to the same histological entity has been debated. This case is important with respect to the pathogenic association between these two disorders. .

Midventricular ballooning Takotsubo cardiomyopathy complicated by transient complete atrioventricular block.

A 63-year-old woman had mistakenly drunk detergent stored in a plastic bottle and was transported to our hospital via ambulance due to unconsciousness. In the emergency room, the monitoring electrocardiogram showed complete atrioventricular block and temporary pacing was thus started. Left ventriculography indicated midventricular Takotsubo cardiomyopathy, although coronary angiograms showed a normal appearance. The atrioventricular block was transient, and the reduced left ventricular wall motion gradually recovered. An electrophysiological study performed before discharge showed no abnormalities in the atrioventricular conduction system. In conclusion, we experienced a case of mid-ventricular Takotsubo cardiomyopathy complicated by transient complete atrioventricular block.

Acute effect of sodium nitroprusside on microvascular dysfunction in patients who underwent percutaneous coronary intervention for acute ST-segment elevation myocardial infarction.

Even in the era of thrombus aspiration and distal protection for ST-segment elevation acute myocardial infarction (STEMI), microvascular dysfunction does exist and improvement of microvascular dysfunction can improve the prognosis and/or left ventricular dysfunction. We evaluated the acute effects of nitroprusside (NTP) on coronary microvascular injury that occurred after primary percutaneous coronary intervention (PCI) for STEMI in 18 patients. The final Thrombolysis in Myocardial Infarction trial (TIMI) flow grade after PCI was 3 in 17 patients and 2 in 1 patient. The index of microcirculatory resistance (IMR) was improved significantly from 76 ± 42 to 45 ± 37 (P = 0.0006) by intracoronary NTP administration. IMR improved to the normal range (IMR < 30) in 9 patients (50%). Higher TIMI flow grade and lower IMR at baseline were observed more frequently in patients whose IMR recovered to normal range after NTP administration. NTP improved the microcirculatory dysfunction at the acute phase in patients who underwent PCI for STEMI and had final TIMI 3 flow in almost all cases.

Sodium bicarbonate for the prevention of contrast-induced nephropathy: the efficacy of high concentration solution.

BACKGROUND: The appropriate dose of sodium bicarbonate to prevent contrast-induced nephropathy (CIN) has not been established. METHODS AND RESULTS: To determine the efficacy of high-concentration sodium bicarbonate, 123 consecutive patients with renal dysfunction undergoing coronary angiography with/without intervention were administrated either high-concentration (group H: 833 mEq/L, n = 87) or low-concentration (group L: 160 mEq/L, n = 36) sodium bicarbonate at the rate of 3 mL/kg/h for 1 hour before the contrast exposure, and followed by 1 mL/kg/h for 7 hours. A total of 77 patients (group H, n = 54; group L, n = 23) without prophylactic continuous hemodiafiltration were analyzed in this study. Urine pH (n = 10 for each group and n = 5 for control) was increased by concentration and time-dependent manner in each group. Urine pH at 3 hours after administration of sodium bicarbonate was significantly higher in group H than group L and control (8.50 ± 0.94 vs 6.95 ± 1.17 vs 5.70 ± 0.97, respectively; P<.001). Incidence of CIN (0% vs 17.3%; P=.005) was lower in group H than group L. Percent change in creatinine within 48 hours was significantly lower in group H than group L (-2.65 ± 9.83% vs 9.14 ± 14.0%; P=.001). Percent change in estimated glomerular filtration rate within 48 hours was significantly higher in group H than group L (3.97 ± 11.8 vs -7.43 ± 13.3; P<.001). CONCLUSION: Administration of a higher concentration of sodium bicarbonate was more effective for urine alkalization and prevention of CIN.

Ruptured plaque in a bare-metal stent 8 years after implantation-Comparison of IVUS and OCT findings.

Optical coherence tomography (OCT) and intravascular ultrasound tomography (IVUS) findings in a patient with very late in-stent restenosis that was manifested as acute coronary syndrome 8 years after bare-metal stent implantation are presented. This case clearly shows the disruption of thin fibrous cap associated with a white thrombus by OCT. A superficial high signal with deep attenuation by OCT, composing more than half of the plaque, was expressed as heterogeneous tissue, mainly composed of echolucent lesion including outside the struts by IVUS. OCT was very useful, like it is for de novo vulnerable plaques, to evaluate vulnerable plaque that had formed in a previously implanted stent. On the other hand, tissue outside the stent struts could be visualized by IVUS. Combined use of OCT and IVUS was useful for understanding the plaque characteristics of ruptured vulnerable plaque that had formed in a previously implanted bare-metal stent even after stabilization of neointimal hyperplasia.

Late in-stent restenosis after sirolimus-eluting stent implantation is related to thrombus formation-Insight from a case with IVUS, OCT, and histological findings.

We experienced a case of very late in-stent restenosis of a sirolimus-eluting stent (SES) (3.0 mm × 18 mm) in the left anterior descending coronary artery in a 62-year-old man with type 2 diabetes mellitus, dyslipidemia, and hypertension. Angina pectoris recurred 39 months after the index percutaneous coronary intervention (PCI). We performed PCI with optical coherence tomography (OCT) and intravascular ultrasound (IVUS) guidance. OCT showed very eccentric low signal plaque with a high signal thin cap on the delayed healing stent struts without intimal coverage. IVUS showed that the plaque was eccentric and hypoechogenic with a "black hole appearance." We used a filter wire (Filtrap™, Nipro, Osaka, Japan) to prevent distal embolism. Filter no-reflow occurred after predilatation. We deployed a paclitaxel-eluting stent followed by postdilatation. After aspiration and Filtrap™ withdrawal, thrombolysis in myocardial infarction 3 flow was obtained. Histopathological analysis revealed that the main tissue was composed of fibrin deposits with scarce inflammatory cells and proteoglycans. This case revealed that fibrin formation is related to very late in-stent restenosis and OCT and IVUS characteristics of this case are shown.

Double chambered right ventricle with severe calcification of the tricuspid valve in an elderly woman: a case report.

INTRODUCTION: Double chambered right ventricle is a rare congenital cardiac anomaly in which the right ventricle is divided into two chambers by an anomalous muscle bundle. The diagnosis of this disorder is difficult in adults. Calcification of the tricuspid valve is extremely rare, and very few cases have been reported. Most cases of tricuspid valve calcification had a congenital disorder with high pressure in the right ventricle. CASE PRESENTATION: We report a rare case of a 71-year-old Japanese woman who presented with chest discomfort, and was found to have a double chambered right ventricle with severe calcification of the tricuspid valve. This abnormality was found by echocardiography, and the diagnosis was confirmed by multislice cardiac computerized tomography, cardiac magnetic resonance imaging, and cardiac catheterization. Our patient rejected surgical repair, and medical therapy with carvedilol was effective to reduce her symptoms. CONCLUSION: Calcification of the tricuspid valve is extremely rare, and considered to be due to high pressure in the right ventricle. To the best of our knowledge, there are no other reported cases of this combination of double chambered right ventricle and calcification of the tricuspid valve.

Angiographic and clinical characteristics of patients with acetylcholine-induced coronary vasospasm on follow-up coronary angiography following drug-eluting stent implantation.

UNLABELLED: Recent studies have shown that drug-eluting stents (DES) induce vascular endothelial dysfunction in both Cypher and Taxus stents. These studies evaluated coronary vasomotion in the peristent coronary segment for 1 lesion with 1 DES. The angiographic and clinical characteristics of real-world patients with coronary spasm following DES implantation have not been well documented. METHODS AND RESULTS: All patients at our hospital who underwent coronary angiography at follow up after DES deployment (Cypher and Taxus stents) between July 2007 and March 2009 were included. We performed an acetylcholine (ACh) provocation test for diagnosing coronary vasospasm in 3 vessels, except in patients with significant stenosis or contraindications to ACh administration. ACh provocation test was positive in 36/55 of the coronary arteries (65.4%) and in 30/42 of the patients with DES (71.4%). There was no difference in the positive rate between patients with and without symptoms. A total of 13/20 asymptomatic patients (65.0%) also showed positive results. In patients with positive results in the ACh provocation test, vasoconstriction at segments distal to the stent was exaggerated compared with corresponding segments in non-stented vessels (0.46 ± 0.27 versus 0.31 ± 0.20, respectively; p = 0.008). Vessels with positive results had a longer stent length compared with those with negative results (31.6 ± 13.6 mm versus 24.2 ± 11.2 mm, respectively; p = 0.049). CONCLUSION: Coronary vasoconstriction was exaggerated at distal segments in DES-implanted vessels compared to non-stented vessel segments and stent length was longer in the ACh provocation test positive group.

Idiopathic ventricular arrhythmias originating from the left ventricular summit: anatomic concepts relevant to ablation.

BACKGROUND: The summit of the left ventricle (LV) is the most superior portion of the epicardial LV bounded by an arc from the left anterior descending coronary artery, superior to the first septal perforating branch to the left circumflex coronary artery. Ventricular arrhythmias (VAs) originating from this region may present challenges for catheter ablation. METHODS AND RESULTS: We studied 27 consecutive patients with VAs originating from the LV summit. The great cardiac vein (GCV) divides this region between an inferior area accessible to ablation and a superior, inaccessible area. Successful ablation was achieved within the GCV in 14 patients and on the epicardial surface in 4. Ventricular prepotentials were recorded at the successful ablation site in 80% of these patients. In 5 patients, ablation was abandoned because of inaccessibility of the catheter to the myocardium or high impedance with radiofrequency application within the GCV. In the remaining 4 patients, epicardial mapping suggested VA origins in a region of low voltage that was located superior to the GCV (inaccessible area), and ablation was abandoned because of close proximity to the coronary arteries or high impedance. A right bundle-branch block, transition zone, R-wave amplitude ratio in leads III to II, Q-wave amplitude ratio in leads aVL to aVR, and S waves in lead V(6) accurately predicted the site of origin. CONCLUSIONS: LV summit VAs may be ablated within the GCV or inferior to the GCV on the epicardial surface, though sites superior to the GCV are usually inaccessible to ablation.

Electrocardiographic and electrophysiological characteristics in idiopathic ventricular arrhythmias originating from the papillary muscles in the left ventricle: relevance for catheter ablation.

BACKGROUND: Idiopathic ventricular arrhythmias (VAs) can originate from the left ventricular papillary muscles (PAMs). This study investigated the electrophysiological characteristics of these VAs and their relevance for the results of catheter ablation. METHODS AND RESULTS: We studied 19 patients who underwent successful catheter ablation of idiopathic VAs originating from the anterior (n=7) and posterior PAMs (n=12). Although an excellent pace map was obtained at the first ablation site in 17 patients, radiofrequency ablation at that site failed to eliminate the VAs, and radiofrequency lesions in a relatively wide area around that site were required to completely eliminate the VAs in all patients. Radiofrequency current with an irrigated or nonirrigated 8-mm-tip ablation catheter was required to achieve a lasting ablation of the PAM VA origins. During 42% of the PAM VAs, a sharp ventricular prepotential was recorded at the successful ablation site. In 9 (47%) patients, PAM VAs exhibited multiple QRS morphologies, with subtle, but distinguishable differences occurring spontaneously and after the ablation. In 7 (78%) of those patients, radiofrequency lesions on both sides of the PAMs where pacing could reproduce an excellent match to the 2 different QRS morphologies of the VAs were required to completely eliminate the VAs. CONCLUSIONS: Radiofrequency catheter ablation of idiopathic PAM VAs is challenging probably because the VA origin is located relatively deep beneath the endocardium of the PAMs. PAM VAs often exhibit multiple QRS morphologies, which may be caused by a single origin with preferential conduction resulting from the complex structure of the PAMs.

Difference in percentage of ventricular pacing between two algorithms for minimizing ventricular pacing: results of the IDEAL RVP (Identify the Best Algorithm for Reducing Unnecessary Right Ventricular Pacing) study.

AIMS: Managed ventricular pacing (MVP) and Search AV+ are representative dual-chamber pacing algorithms for minimizing ventricular pacing (VP). This randomized, crossover study aimed to examine the difference in ability to reduce percentage of VP (%VP) between these two algorithms. METHODS AND RESULTS: Symptomatic bradyarrhythmia patients implanted with a pacemaker equipped with both algorithms (Adapta DR, Medtronic) were enrolled. The %VPs of the patients during two periods were compared: 1 month operation of either one of the two algorithms for each period. All patients were categorized into subgroups according to the atrioventricular block (AVB) status at baseline: no AVB (nAVB), first-degree AVB (1AVB), second-degree AVB (2AVB), episodic third-degree AVB (e3AVB), and persistent third-degree AVB (p3AVB). Data were available from 127 patients for the analysis. For all patient subgroups, except for p3AVB category, the median %VPs were lower during the MVP operation than those during the Search AV+ (nAVB: 0.2 vs. 0.8%, P < 0.0001; 1AVB: 2.3 vs. 27.4%, P = 0.001; 2AVB: 16.4% vs. 91.9%, P = 0.0052; e3AVB: 37.7% vs. 92.7%, P = 0.0003). CONCLUSION: Managed ventricular pacing algorithm, when compared with Search AV+, offers further %VP reduction in patients implanted with a dual-chamber pacemaker, except for patients diagnosed with persistent loss of atrioventricular conduction.

Idiopathic left ventricular arrhythmias originating adjacent to the left aortic sinus of valsalva: electrophysiological rationale for the surface electrocardiogram.

BACKGROUND: Idiopathic ventricular arrhythmias (VAs) may be amenable to catheter ablation within or adjacent to the left sinus of Valsalva (LSOV). However, features that discriminate these sites have not been defined. The purpose of this study was to determine the electrocardiographic and electrophysiological features of VAs originating within or adjacent to the LSOV. METHODS AND RESULTS: We studied 48 consecutive patients undergoing successful catheter ablation of idiopathic VAs originating from the left coronary cusp (LCC, n = 29), aortomitral continuity (AMC, n = 10) and great cardiac vein or anterior interventricular cardiac vein (Epi, n = 9). A small r wave, or rarely an R wave, was typically observed in lead I during the VAs and pacing in these regions. An S wave in lead V5 or V6 occurred significantly more often during both the VAs and pacing from the AMC than during that from the LCC and Epi (p < 0.05 to 0.0001). For discriminating whether VA origins can be ablated endocardially or epicardially, the maximum deflection index (MDI = the shortest time to the maximum deflection in any precordial lead/QRS duration) was reliable for VAs arising from the AMC (100%), but was less reliable for LCC (73%) and Epi (67%) VAs. In 3 (33%) of the Epi VAs, the site of an excellent pace map was located transmurally opposite to the successful ablation site (LCC = 1 and AMC = 2). CONCLUSIONS: The MDI has limited value for discriminating endocardial from epicardial VA origins in sites adjacent to the LSOV probably due to preferential conduction, intramural VA origins or myocardium in contact with the LCC.